Curvaton in large field inflation

We comprehensively explore the quadratic curvaton models in the chaotic inflation. In the light of the BICEP2 result r ≈ 0.2, all model parameters and relevant observables are computed. It is found the curvaton field value is constrained into a narrow range, σ * = (10 −2 –10 −1 ) and the running of the spectral index is n s '≳−10 −3 . We show that if the curvaton is added, the models are heavily degenerated on the n s - r plane. However, introducing a new plane, the degeneracy can be resolved. To distinguish the curvaton models, precise measurements of not only r but also n s ' and the tensor tilt n T are required.